Concrete floor construction.



C. L. MEYER,

' CONCRETE FLOOR CONSTRUCTION.

'APPLICATION FILED MAIL-6, 19w.

Patentd Apr. 16, 1918.

Zizziivzbr Cfiarzsll/[yer tmrrnnsrn CHARLES L. MEYER, or om;

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concnnrn ritoon cons'rnncrron.

To all whomz'tmag concern:

Be it known that I, CHARLEs'L, MEYER, a citizen of the United States, residing at Omaha, in the county of Douglas and State of Nebraska, have inventcdcertain new and useful Improvements in Concrete Floor Constructions, of which the following is a speci fication; g

This invention relates to the general art of concrete building structures, and has ,ref-

erence more particularly to improvements concrete floors for bulldings. Those familiar with theart of concrete floor .construc-- tion are aware that the floor proper is sup-' 7 ported by girders, which in turn are connected sidewise by a series of joists'b'eneath the floor, the girders, joists and overlying .floor being formed integrally of concrete, and the girders commonly having metal reinforcing rods lying inand lengthwise of the lower or tension region thereof. The forms or-molds usually of a generally inverted U shape, over which the'concrete is poured, extend from girder'to girder and are so positioned with respect to each other that the joists are formed between adj acentsides of the spaced rows of forms, the end form of each row having a vertical or substantially vertical end wall which providesa'portion of the side wall of the girder mold. A construction of this character is typically illustrated in Letters Patent of the United. States No.

, 1,106,665, granted to me August 11, 1914,

although in the said patent the girders are shown as having lI-beam' reinforcements-and the joists as having tension-rod reinforce. ments. I 7

My present improvements are more part1c- I ularly, although not exclusively, designed 40 and adapted for constructions employing 4 solid concrete girders, with or without tension-rod reinforcements; and one of the 'objects of the invention is to provide a com- I bined integral concrete floor, girder and joist e5 construction of such a form that the girders, joists and floor proper will be reinforcedat their points of junction toresist shear strains without using an excessive or unnecessary amount of concrete or reinforcing 50, metal. Another object of the invention is to provide an improved juncture of both. the 1 floor proper and the joists with the girder, which, through a more scientific distribution of the concrete, will combine equal or greater strength with an econom in the amount of concrete heretofore use As will appear Specification of Letters Patent. Application filed March 6, 1917. Serial No. 152,544.,-

mon in this. type of structure.

Patented m, as, rare;

from the following detailed description and the drawing,the objects are attained by a construction wherein the joists are gradually invention, the same being broken out and in horlzontal section at the point of juncture of?- two of the floor joistswith the girder;

Fig. 2 is an enlarged vertical section taken on the line f2-2 ofvFig. 1;

Fig. 3 is averticalsection at right angles of Fig. 2'; and

.Fig. 4 is a perspective detail, partly broken out, of an end-form or mold through to that of Fig. 2, and taken on the line 3 3 the agency of which the improved construction isobtained.

Referring to the drawing, 5. designates the floor proper, 6 the girders, and 7 the joists of myimprovcd floor structure,'all of these elements constituting an integral or, onepiece structure of solid concrete, with reinforcing tension rods 8 preferably employed in the tension region of the girders, as com- By reference to Figs. 1 and 3, it will be observed .that the end portions of the joists 7 are gradually widened horizontally for some distance as they approach and merge into the sides of the, girders 6, such widened end portions bein indicated by'the reference numeral/Z. y reference to Figs. 2 and 3,

it will also be observed that the portions of I the floor 5' lying between adjacent joists are gradually thickened vertically for some distance as they approach and merge into the upper portion of the girder, such thickened floor portions lying wholly above the neutral 'axis of the latter and being indicated by the reference numeral 5'.

A simple'and' practical means by which the describedconformation may be produced is a tapered -end mold section such as is shown in perspective detail in Fig. 4' and in longitudinal and transverse section in Figs.

2 and 3, respectively. This end section,

it will be observed, is formed with side walls l a decrease, in the quantity of concrete used,

8] which converge toward thevertical end wall 9 and also gradually decrease in height I 7" of the joist molded between two latertoward the latter, so that the top wall 10 of the mold section is downwardly inclined toward the end wall 9, as clearly shown in Fig. 2. llhe convergent taper of the side walls'8 produces the widened end formation ally adjacent end sections; while the downward inclination or taper of the top wall 10 produces the gradually thickened floor portion 5 between adjacent joists and lying next to the girder; but this thickening and reinforcing of the fioor structure is accomplished Without any increase, but rather with for the reason that the end form of the mold is extended inwardly into substantial vertical alinement with the side of the lower portion of the-girder, thereby eliminating the lower portion of the cap or shoulder of the T girder that lies below the neutral axis of the latter, and which is practically valueless for strength purposes. An example of a solid concrete T girder having such a.

I shoulder on either'side of the main body of the girder may be seen in-Figs. 3 and 6 of Letters Patent to Dale, No. 1,131,479, March 9, 1915, this being the common and usual form of solid concrete girder employed where steel K-beams are not used as the chief load-carrying element of the girder. My invention enables a solid concrete girder to be used, and yet eliminates a considerable amount of useless concrete below the neutral axis, and at the same time, through the thickening of the fioor proper at its region of juncture with the girder, ofi'ers an in-' creased resistance to shear strains and also reinforces the upper or compression region ofthe girder by giving to the latter a-special IT-form in cross section characterized A combined T-girder, joist and by a gradually increasing thickness of the cap. portions as they merge into the body,

, as seen in Fig. 2. The described widening of the joists where they merge into the sides of the irder also affords an increased retion employing the shouldered form of solid concretegirder above referred to.

llt is believed that the structure of my invention and the advantages mhering therein will be understood from the foregoing without further description; and, While I have shown and described the preferred embodiment of the invention, it should be obvious that the details of shape and'proportions are capableof modification and variation with- Y.

in the scope of the invention as defined in the following claim.

I claim:

floor construction formed integrally of concrete, and

wherein the end portions of the joists lying beneath'the cap of the girder are of gradually increasing width and decreasing depth asthey merge into the stem. of the girder,.

and the floor portions which merge into and define the cap of the girderlying above and between said end portions of the joists are of gradually increasing thickness as they approach the stem of the girder and lie wholly above the neutral axis of the latter.

CHARLES L. MEYER. 

